flutter update-packages --offline does not pass --offline to pub #193423

The flag is accepted and used to reject incompatible combinations, but never reaches pub, so the command resolves over the network.

In packages/flutter_tools/lib/src/commands/update_packages.dart at 3.47.5, offline is read once and used only in two guards:

final bool offline = boolArg(_keyOffline);          // :139
if (forceUpgrade && offline) { throwToolExit(...) } // :151
if (cherryPicks.isNotEmpty && offline) { ... }      // :159

Both pub invocations in that file omit it:

Future<void> _pubGet(FlutterProject project, bool enforceLockfile) async =>
    pub.get(context: PubContext.pubGet, project: project,
            enforceLockfile: enforceLockfile);                     // :241

await pub.interactively(<String>['upgrade', '--tighten', '-C', projectTempDir.path],
                        context: PubContext.updatePackages, ...);  // :293

Pub.get has the parameter and forwards it (lib/src/dart/pub.dart:151, and if (offline) '--offline' at :342); other callers such as create.dart and widget_preview.dart do pass it.

Observed with the network unreachable, a pub cache holding every package the lockfile names, and PUB_HOSTED_URL left at its default:

$ flutter update-packages --offline
Resolving dependencies...
Downloading packages...
ClientException with SocketException: Connection failed
  (OS Error: Network is unreachable, errno = 101), address = pub.dev, port = 443,
  uri=https://pub.dev/api/packages/archive/advisories
Failed to update packages.

pub's own advisories fetch is offline-guarded (_fetchAdvisories, third_party/pkg/pub/lib/src/source/hosted.dart:566, "Don't attempt to fetch advisories in --offline mode"), which is consistent with pub simply never being told it is offline here.

Two further observations from the same environment, for whoever picks this up:

• With --offline reaching pub, the command still does not complete: it re-resolves rather than honoring the lockfile, and had not finished after 15 minutes. dart pub get --offline against the same cache returns in under a second.
• flutter doctor similarly runs dart pub ... get for packages/flutter_tools without --offline; with no network that step fails and doctor still exits 0.

Context: packaging the SDK for Yocto, where builds run with the network off by policy.